Newt Gingrich finished with 25 percent of the vote, ahead of Ron Paul's 19 percent. Former Pennsylvania Sen. Rick Santorum received 12 percent of the vote.

Romney now leads the Republican field with 81 delegates, well ahead of Gingrich's 27.

Gingrich aids told reporters the candidate would retool his strategy to generate a more positive campaign. Romney, meanwhile, turned his attention to President Barack Obama following the announcement of his Nevada win.